(1.) Field of the Invention
The instant invention is directed to the field of flow restriction devices, and more particularly, to a bimodal flow restriction device for torpedo tubes.
(2.) Description of the Prior Art
Conventional torpedo tubes have longitudinal lands which run the length of the torpedo tubes and circular lands which are normally located at the tube section-intersect points and on both the breech and muzzle ends of the torpedo tubes. The lands support the torpedoes as well as equipment associated with torpedo launch and other controllers and ancillary equipment.
To eject a torpedo, a pump directs a high pressure plume of water behind the weapon. The pressure unbalance between the tail and nose of the weapon results in a force unbalance, which ejects the weapon. In some torpedo tubes, the diameters of the tubes are larger than the diameters of the torpedoes, and annular fluid flow paths around the weapons are thereby created. A great deal 3 of the pump's energy is expended in ejecting the annulus of water in lieu of the weapon. This severely reduces the efficiency associated with ejecting the weapon.